That depends if we're talking about volume, quality or consistency.
I realise that you're a fan of TSR-era lore. I am too. I have no problem agreeing that measured only by quantity, it is hard to fault. However, once we stray into a discussion of quality or consistency, the lore produced during TSR's time at the helm is hardly without its own problems.
In terms of quality and consistency, 1e/2e era lore is a real mixed bag. There are many products (and product lines) with deeply problematic lore: lore that is misogynist or racist by today's standards, lore that is plain silly (the Dragonlance product Gnomes-100, Dragons-0 has an encounter with an ocean-dwelling kraken inside Mount Nevermind that requires the use of a nearby steam-powered laser to resolve) and a vast quantity of lore that contradicts other lore. Sure, TSR did make some effort to try to avoid outright contradictions, but given the sheer volume of their output, it isn't hard to find contradictions when researching almost any topic.
I enjoy my library of TSR products for what it is. But I certainly don't share your view that it is in any way a flawless body of lore.